Much appreciated. I was thinking friction of powder or turbulence must be the factors.

Stephen

There is a theory that the sharper shoulder angle improves accuracy and efficiency due to
flame front improvements but it is just theory and the 30o shoulders have proven themselves
in bench rest cartriges as stated.

The only provable thing is that less body taper improves the grip on the chamber lessening
bolt loading. one of the reasons that the "Improved cases" will show less signs of pressure
because the case is not pushed back as hard on the bolt.(It's not much but it does seam to
make a difference).

I have a .338 edge a.i. 40 deg my buddy has a reg .338 edge, both guns built by the same smith, there is no real case capacity improvment to talk about, both guns shoot very well ,I can get a 1/2 grain more powder before seeing psi signs. on average my gun shows about 30 fps faster then his but I also have 1 " more barrel. The only real difference I see is that my reloading dies cost double of his. This is our findings in our guns take it for what it is. thanks